PTRAN, Version 1.1, uses a Monte Carlo program to calculate the transport of proton beams through extended media. The PTRAN code uses 50 to 250 MeV beams through water phantoms. Multiple scattering and Coulomb interaction energy loss mechanisms are taken into account along with nonelastic nuclear interactions. PTRAN calculates deposition of energy as a function of depth and radial distance from the beam, energy spectra of the primary protons as function of depth. Both 1 and 3 dimensional calculations are available.

The PTRAN system uses several cross-section preparation programs and two main codes, PTRAN3D and PTRAN1D. The heart of the calculations is the Monte Carlo model which is based on the condensed-random-walk method (BERGER, 1963), and takes into account the following types of events occurring in successive short track segments: (a) energy-loss straggling in Coulomb collisions with atomic electrons, (b) multiple-scattering deflections due to elastic scattering by atoms, and (c) energy loss in nonelastic nuclear reactions. Data preparation programs facilitate the sampling of energy losses (VAVILOV, 1957) and angular deflections (MOLIERE, 1948). The initial proton stopping powers and ranges in water use PSTAR (NISTIR 4999, RSIC PSR-330).

Using the 80486/87 50 MHz PC, the PTRAN3D took 56 minutes of run time, the PTRAN1D took 35 minutes. On a 80386/87 33 MHz PC, all the data preparation programs were run using less than a minute, including the interactive requests for parameter input.

CCC-0618/01

The test case included in this package was executed on a 66-MHz PC/80486. Run times for the main programs were: 42 minutes for PTRAN3D; 26 minutes for PTRAN1D.

The executable codes were compiled and linked using Lahey F77L3/EM32 version 5.0 which requires a 80386 w/80387 math co-processor or better. The PTRAN1D and PTRAN3D required 7.5 Mbytes of RAM to run while the other executables need less than 3.5 Mbytes RAM. No special graphics monitor or printer is necessary. The total set of codes with executables, input files, and output files will occupy at least 15 Mbytes of hard disk space.

CCC-0618/01

PTRAN was installed by NEA-DB on a DELL 466/L PC with a 66-MHz 80486 processor and 16 Mbytes of RAM.

MS-DOS version 3.3 or higher is required. The memory requirements of several Mbytes of RAM require DOS Extender software or equivalent to access the memory above 640 Kbyte. The Lahey F77L3/EM32 version 5.01 with Phar Lap's DOS Extender was used to compile and link the executables included in the distribution diskettes. When running these executable programs there needs to be access on the hard drive to a error file F77L3.EER supplied by Lahey and included in the diskettes.

CCC-0618/01

Installation at NEA-DB was done under MS-DOS Ver.6.2. The source codes were compiled using the Lahey F77L-EM/32 FORTRAN compiler version 5.20.